Douglas Walker was 10 years old when his father, Air Force Brigadier Gen. Kenneth N. Walker, went missing.

The elder Walker, the highest-ranking officer missing in action during World War II, was one of 11 crew members onboard the San Antonio Rose B-17 Flying Fortress heavy bomber, which was last seen under heavy attack from Japanese fighters near what is now Papua New Guinea. The crew were first declared missing in action on Jan. 5, 1943, and subsequently declared killed in action on Dec. 12, 1945.

"One of the problems with the case is there was no eyewitness," Walker said. "No one saw the plane in its last minutes."

He assembled a working group to pore over "mountains of documents to uncover the key elements to help us put together the likely trajectory of the plane and the crash site," he said, noting it took time and he attributed much of the success to the evolution of the internet.

Now, nearly 75 years later, Walker still is pushing for a search for the plane's remains. He's enlisted the help of U.S. Sen. Richard Blumenthal, D-Conn., who on Nov. 9 introduced a resolution with U.S. Sen. John Boozman, R-Ariz., that seeks to honor the crew by pledging to continue the search for the plane. Senators representing states, from which the crew members hailed, also have signed on.

"I think it will keep the issue alive and serve as a significant signal that this is not going away," Walker, 84, of New Canaan said in a phone interview Friday.

He joined Blumenthal at a news conference in New Haven earlier in the day to announce the resolution.

"The basic principle is that our U.S. military leaves no one behind," Blumenthal said by phone Friday. "Our nation leaves no one behind. We keep faith with our POWs missing in action. Some of the POWs have come home. The missing in action have not. We keep faith with them by continuing to search, and recovery, if possible."

The Department of Defense's POW/MIA Accounting Agency conducts searches for the remains of prisoners of war and those missing in action. The agency focuses mainly on Vietnam, "but were persuaded to begin working in this area," Blumenthal said.

There were two search missions in August and April of this year to search for the San Antonio and other B17s "forced down in this area," according to Blumenthal. Another search is planned for 2018, he said.

As for the timing of the resolution, introduced just before Veterans Day, Blumenthal said he "thought it was appropriate to do it now, even though it's a war that for most people is difficult to remember or they've only read about it."

"These guys were part of our greatest generation and they deserve this respect," he added.

In this handout from the U.S. Air Force, Brig. Gen. Kenneth N. Walker of Glendale, Calif., is shown in this undated photo. Nearly 75 years after his father disappeared during a bombing mission over a remote Pacific island, Douglas Walker, the son of the highest-ranking recipient of the Medal of Honor still listed as missing from World War II, is pushing for renewed interest in finding the crash site and the remains of the crew. (U.S. Air Force/AP Photo)